Need a Borescope Tutorial|Restoration, Repair and Maintenance|Forum|Winchester Collector

Thanks, gents.  Steve I read almost all of the prior thread (stopping only when it drifted into Mopar) and the advice there and here is sound – look at as many barrels as possible, preferably one new by a customer barrel maker noted for its barrels.  I don’t have any of those on hand myself, but can turn up some that are new and unfired.  One I’m thinking of is a little Ruger (red pad) 77RSI in .250-3000 Savage with a 1 in 10 twist that has always shot remarkably well for me, even though it came from Ruger’s large volume barrel subcontractor of dubious, it-or-miss memory.  The round count is relatively low and a good many of what went down the bore were handloads based on SR4759 cooked up specifically as “turkey loads” for Rio Grande gobblers. 

I can probably find some pristine bores to examine. What I’ve been looking for is a good image of guaranteed, actual throat erosion, which is what I interpreted the black cobblestones to be.  

Somebody once heavily involved in High Power competition wrote one way to mess with your competitor’s mind was to offer to borescope his rifle before the start of the event. One look at the inside of his super-accurate competition rifle’s barrel was so upsetting the poor guy couldn’t concentrate during the match and his scores went to hell.  

The cobblestone rifle at issue is not a Winchester but rather a heavy barrel varmint .243 made in Belgium and Finland, built in 1971, the brand of which shall remain nameless. Weather permitting, we shall take it to the range next week and see what’s what, cobblestones and all.  

TXGunNut said
Bill-

My bore scope is out of service but not before I learned a bit about bores. First, only a rifle capable of shooting well under MOA needs a pristine bore to perform at its best. The 270 in question was probably only capable of 1.5 inches when it was new. Nothing wrong with that! Second, a bore scope shows us the throat erosion that often begins to show up after a few hundred rounds. Third, an old Winchester bore that resembles a sewer pipe will deliver respectable accuracy with only a little work on tailoring the loads. Fourth, guys who sell rifle barrels love bore scopes!

 

Mike

  

Concur.  Of the several pre-64 Model 70 rifles of my acquaintance, none of which were purchased new and all of which had seen an unknown round count, all would make 3-shot groups of between 1.25 and 1.75 MOA at 100 yards with just about any reasonable load, which was plenty for the purpose intended. My 1950 SG ’06 – equipped only with a Lyman 48 and no screw-in aperture and plain old Remington 180 grain PSP Core-Lokt – once shot a 5-shot .85″ 100 yard group. Once.  Of course I cut that one out and pasted it into my Book of Stellar Achievements.  

The B-word rifle in question was intended by its maker to be a varmint rifle, I presume, because the barrel is the sightless heavy one, not the iron sighted pencil version.  That being said, while experiencing buyer’s remorse for having paid too much for something questionable, it occurred to me that, since it was a VARMINT rifle, it might have been fired considerably more in a short session than your typical deer gun. That, plus the .243 chambering, which can be a barrel burner because of its case-to-bore ratio, caused me to become curious about the state of the bore.  Because of my raccoon-like innate curiosity, which has gotten me into more trouble than I’d care to admit, even if the thing shoots half MOA groups at the bench, I’d still want to know what it looks like inside.  While I’ve got you on the phone, what do you know about Simmons scopes?